Merge branch '4.4' into 5.2

* 4.4:
  Minor change to use DateTimeImmutable instead of DateTime
  [Twig] Add missing space
  [Validator] Mention doctrine-bridge in the UniqueEntity constraint

Author: javiereguiluz

doctrine/events.rst

@@ -76,7 +76,7 @@ define a callback for the ``prePersist`` Doctrine event:
              */
             public function setCreatedAtValue(): void
             {
-                $this->createdAt = new \DateTime();
+                $this->createdAt = new \DateTimeImmutable();
             }
         }
 

performance.rst

@@ -279,7 +279,7 @@ You can also profile your template code with the :ref:`stopwatch Twig tag <refer
 .. code-block:: twig
 
     {% stopwatch 'render-blog-posts' %}
-        {% for post in blog_posts%}
+        {% for post in blog_posts %}
             {# ... #}
         {% endfor %}
     {% endstopwatch %}

reference/constraints/UniqueEntity.rst

@@ -10,6 +10,11 @@ using an email address that already exists in the system.
     If you want to validate that all the elements of the collection are unique
     use the :doc:`Unique constraint </reference/constraints/Unique>`.
 
+.. note::
+
+    In order to use this constraint, you should have installed the
+    symfony/doctrine-bridge with Composer.
+
 ==========  ===================================================================
 Applies to  :ref:`class <validation-class-target>`
 Options     - `em`_

reference/constraints/UserPassword.rst

@@ -12,7 +12,7 @@ password, but needs to enter their old password for security.
 
 .. note::
 
-    In order to use this constraints, you should have installed the
+    In order to use this constraint, you should have installed the
     symfony/security-core component with Composer.
 
 ==========  ===================================================================